Artificial tooth-crown and backing.



4 'G.GARR. ARTIFICIAL TOOTH GROWN AND BACKING.

APPLICATION FILED MAR. 13,1912.

1,035,688. Patented Aug. 13,1912.

WITNESSES INVENTOR PB Geo? Caz/v g K 1- GEORGE CARR, oF'PA'rnR soN, NEWJERASEY.

ARTIFICIAL TOOTH-CROWN AND BACKING.

specification of Letters Patent. Patented Aug. 13, 1912.

Application filed. March 13, 1912. Serial No. 683,460.

To all whom it 11'2-03 concern Be itknown that I, GnoRG'n CARR, a citizen of. the United States, residing at- Paterson, 1n the county of Passaic and State of New Jersey, have lnvented certain new and use-.

ful Improvements in Artificial Tooth- Crowns and Backings, of whichthe following is a specification.

This invention relates to certain new and useful improvements in artificial tooth crowns and backings therefor, and the invention consists of the improved tooth crown and backing which I will hereinafter describe and point out in the claims.

' A leadingobject of the invention is to provide artificial teeth with all porcelain cusps for bicnspids and molars and an all porcelain tip for the an'teriors (cuspids, lateralsand centrals) and to so fashion these teeth that they are readily removable during construction and interchangeable in case of necessity, said teeth being capable of use with a backing or plate which is fashioned to conform to corresponding portions of any of the teeth of a given mold.

In the accompanying drawing forming part of this specification, and in which similar reference characters indicate-like parts in the several .views;Figure 1 is a perspective View of, an artificial tooth'crown embodying my invention and fashioned to receive the backing or plate. Fig. 2 is a perspective view of the backing or plate for the tooth crown of Fig. 1. Fig. 3 illustrates a tooth crown fashioned slightly modified from the construction shown in Fig. 1. Fig; l is a backing or plate designed for use with the tooth crown of Fig.3. Fig. 5 is a crosssection of the tooth crown shown in Fig. 1 with the backing plate attached. 6 is a sectional view showing an anterior tooth crown constructed according to my invention.

In the drawing l have illustrated in Fig. 6, an anterior tooth. crown and in Figs. 1 and 3, a molar and it will he understood that the scopc'of the invention includesbicnspids,

molars, etc... and that. the two instances shown may he considered as illustrative of any and all kinds and sizes of teeth.

- The tooth crown, A. is of porcelain and is molded and baked in the manner well known in this art, and, therefore, not'necessary to be described hereln. A substantial portron of the rear of the base of the tooth is removed, but sufficient of the front remains to giwe the tooth the desired-strength and appearance and to leave all porcelain cusps, for bicnspi'ds and molars have occlusal surfaces of all porcelain; the six anteriors have all porcelaintips as well as an allporcelain labial surface. I

The cut-away or reduced base portion of the tooth is ground down on two opposite corners in lateral planes to form the transversely inclined surfaces, a, 6. .These inclined surfaces may be at anydesired angle crosswise of the tooth and I'hav'e found in practice that the angle of is well suited;

for my purpose, although I do not restrict the invention to this or any specific angle. hat-ever the angle given the opposite sides of the, reduced base portion of the tooth, said angle should be common to all teeth of a given; mold, including bicuspids, molars, etc, in order that theteeth may be readily renewable and interchangeable and used in connection with a backing of angular crosssection,'and which angle is similarto thatwhich is given the base of the tooth, and which is represented at a, Z); in other words, the angular surfaces, a, 7), will be common to teeth ofall widths and'lengths which will make any given mold interchangeable, in case of necessity, without removal of the abutment or bridge, as an accident, or where the shade of tooth decided on was found to be incorrect; also, if a tooth is found to be too long, or too short, after bridge orcrown work has been constructed. Also allows the removal of crown while soldering and does away with the possibility of .checking the porcelain or changing the shade by passing from front to hack of thetoolh. thus giving the upper portion of this part of the tooth a suhstai'itially widenea'l V-shape in crossscrtion. as shown in Fig. 3: r. if desired, the c1'oss-s .a-tional shape may he modified to represent snhstantiall a flattened V-form.

in which case the two lransvcrselv inclined surfaces will be connected by an intcrmediate flat urface, as shown in Fig. 1'. ln either of the instances shown. the cutting down of the base results in the formation of a vertical shoulder or wall, (I, at the front ends of the inclined surfaces, a, b, and

I back of this shoulder or wall and closer thereto than to the back end of the tooth, a hole, e, is made vertically or at an angle into the tooth, said hole being of desired depth for a-retainiiig pin, which I .will hereinafter describe, and said hole being positioned in the center of the arch formed by the inclined surfaces, a, b.

In connection with the tooth fashioned as hereinbefore described, I use a backing, B, as illustrated in Figs. 2 and 4, said backing being formed of'metal of a character suitable fordental purposes and being bent at two opposite sides to form the laterally extending inclined planes or wings, f, {1, and being further bent to form a vertical flange,

' h. at one end thereof. The backing is thus given an arched form and the cross-section of the arch Will correspond to the transversely inclined surfaces, a, b, of the tooth,

so that the tooth will readily conform to the backing, said backing having a fixed pin, 1, adapted to enter the hole, e,in the tooth, and correctly center said tooth, and the vertical flange, h, being adapted to seat against the corresponding shoulder or wall, d, formed "on the tooth. I prefer that the fixed pin, I,

shall have its upper end projecting above the crown of the arch of the plate shown in Fig. 4 and also in the. flat middle portion of the plate shown in Fig. 2. The projection may be about'3/4 the height of the vertical flange, hand this project-ion gives added strength to the plate, as in practice solder fills in all the space up even with-the top of the wall when the crown or bridge is-complete. The pin, therefore, braces and strengthens the plate at the point where great strength is desired.

From the foregoing it will be apparent to those skilled in this. art that as all the crowns of a common mold, after baking, are ground down to form the laterally-inclined surfaces, a, b, in either of the instances shown, or in any other of a. like character, and as the backing is fashioned with corresponding inclined surfaces, said crowns will; accurately fit the same backing and accordmgly the teeth are interchangeable; they require less solder in. construction work; they are stronger at the points heretofore rearded as weakest in other crowns; the backmg will be of uniform shape, being struck up from a' single die, and hence accurately 4 fit the molds; the teeth are more sanitary and so far as I know have-the only anterior crowns which are interchangeable.

Having thus described my invention what I claim as new and desiretosecure by Letters Patent is 1. An artificial tooth cusp havin a base, the rear portion of which is re need in height/tn form a vertical shoulder on the rear of the cusp, said reduced rear portion being ground along two opposite corner portions to form transversely diverging surfaces.

2. An artificial toothcrown having a base,

the rear portion of which is reduced in height to form a vertical-shoulder on the rear'of the cusp, said reduced rear' portion being ground along two opposite corner portions toform transversely.diverging surfaces, and a backing bent to form' an gular sides conforming to and seating upon the,

diverging surfaces of the base. a v

3. An artificial tooth crown having a cutaway base ground along two opposite corner :portions to form transversely diverging surfaces, and a backing bent to form angular sides conforming to and seating upon the di verging surfaces of. the base, saidbrown having a vertical shoulder on its rear andsaid backing being formed with a vertical flange to seat against said shoulder.

4. An artificial tooth crown having a cutaway base ground along two opposite corner portions to make the base substantially V- shaped in cross-section, said base having a hole, and a backingbent to conform to and fit the cross-section of the base and having a pin to engage the hole therein.

'An artificial tooth crown having a base,

the rear portion of which is reduced in height to form a vertical shoulder on the rear of the cusp, said reduced rear portion being ground along two opposite corner portions to make the base substantially V- shaped in cross-section, said base having a hole, and a backing bent to conformto and fit the cross-section of the base and having a pin to engage the hole therein, said pin also projecting above the upper surface of the acking.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE CARR.

Witnesses:

LILLIAN C. A. CARR, MARTHA Bazoonr.

copies ofthis patent may be obtained for m cent! each, by droning the Commissioner of Patents.

wuhiiigton, D. 0." 

